unit 21 formula presentation 1using formula presentation 2constructing formulae presentation...
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Presentation 1Using FormulaPresentation 2Constructing FormulaePresentation 3Negative NumbersPresentation 4Temperature DifferencesPresentation 5Substitutions into FormulaePresentation 6More Complex FormulaePresentation 7Changing the SubjectPresentation 8Pendulums
Unit 21Formula21.1 Using Formula
What are the perimeter length and area if and?
The perimeter length, P, and area, A, of a rectangle are given by the formulae
where l is the length and w the width of the rectangle.Solution
Unit 21Formula21.2 Constructing Formula
When repairing air conditioning systems, an emergency engineer charges a basic fee of J$3000 plus J$1200 per hour.QuestionFind a formula for calculating the engineer's charge for repair work which takes n hours.SolutionLet C = ChargeSo C = fixed charge + hourly charge no. of hours C = J$3000 + J$1200 nC = J$3000 + J$1200n????QuestionWhat does the engineer charge in total if the repair takes 6 hours?SolutionC = J$3000 + J$1200 6C = J$3000 + J$7200C = J$10200?????
Unit 21Formula21.3 Negative Numbers
Rules to remember
4 + (10) = 66 + 8 = 24 5 = 96 + (7) = 13(40) (5) = 8(24) (3) = 8(40) (5) = 8(6) 7 = 42
Unit 21Formula21.4 Temperature Differences
Use information given on the above to answer these questions.What is the difference in temperature between
Kingston and Singapore4Kingston and London25Kingston and Vancouver29London and New York3London and Sydney26Lima and Kingston0Oslo and Kingston30Moscow and Kingston34????????
Unit 21Formula21.5 Substitution in Formula
l = (40 + 0.02T) cmThe length of a metal rod changes with temperature according to formula above; where T is the temperature in CQuestionWhat is the length of the rod when(a) T = 50C(b) T = 10C
(a)l = (40 + 0.02 x 50) cm = (40 + 1) cm = 41cmSolution??
(b)l = (40 + 0.02 x 10) cm = (40 + 0.2) cm = 39.8cm????
Unit 21Formula21.6 More Complex Formula
The formulagives the focal
length f for a lensQuestion What is the value of f, if u = 10cm and v = 8cm
Unit 21Formula21.7 Changing the Subject
The formula that connects Celsius (C) and
Fahrenheit (F) is
Rewrite the formula in the form C = ......Solution
Take 32 from both sides of the formulaMultiply by 5throughout
?Divide by 9throughout
Unit 21Formula21.8 Pendulums
Make l the subject of this equation.
?The period of revolution, T, of a pendulum of length l is given by the formula when G is a constant.
Divide both sides by to giveSquare both sidesMultiply both sides by G to give???